The stimulus payment is based on the 2020 return. It is perfectly legal for you to get the stimulus on your 2020 return if you can’t be claimed as a dependent even though your parents may have gotten a stimulus payment for you on their 2019 return when you were their dependent.
I assume that in 2019 you were a dependent on someone else's tax return. That individual may or may not have received a dependent stimulus payment last May and last January.
Are you claiming yourself on your 2020 Federal tax return? No one is claiming you as a dependent?
If so, you may qualify for one or both of the stimulus payments through the Recovery Rebate Credit.
If you have not received one or either of the stimulus checks, you may receive your payment in the form of a Rebate Recovery Credit on line 30 of your 2020 Federal tax return when you file.
TurboTax will compare your one or two stimulus payment amounts to the computations within TurboTax. The computations within TurboTax are based upon the information that you have entered into the tax software. If you are due an additional amount, it will be issued as a Rebate Recovery Credit (RRC) on line 30 of the 2020 1040 tax return.
In TurboTax Online, you are prompted to input stimulus check 1 and stimulus check 2 information under Review down the left hand side of the screen.
You can access your stimulus check choices by following these steps:
See also this TurboTax Help.